IL47436A

IL47436A - Process for the manufacture of an addition compound of sorprocess for the manufacture of an addition compound of sorbic acidand potassium sorbate (potassium disorbate) bic acid-and potassium sorbate (potassium disorbate)

Info

Publication number: IL47436A
Application number: IL47436A
Authority: IL
Original assignee: Hoechst Ag
Priority date: 1974-06-12
Filing date: 1975-06-06
Publication date: 1977-12-30
Also published as: IL47436A0; AU8203775A; GB1506469A; FR2274598A1; ZA753502B; DE2428411A1; NO752076L; AT340381B; SE7506562L; BR7503685A; CA1048538A; BE830187A; FI751724A; DD118072A5; IT1038853B; FR2274598B1; NL7506752A; JPS5111707A; DE2428411C2; DK263375A

Abstract

Process for the manufacture of a molecular compound of sorbic acid - potassium sorbate by means of crystallization from a solution of sorbic acid and potassium sorbate. [US4132733A]

Description

PBOGESS FOR THE MANUFACTURE OP AH ADDITION COMPOUND OF SOBBIC AND POTASSIUM SORBATE It is known that sorbic acid produces with potassium bate a readily crystallizing molecular compound of the sition which may be called in analogy to sodium the facture of this compound has not been described Whilst sorbic potassium sorbate and to a lesser extent also calcium sorbate are extensively used as preservatives by the foodstuff potassium disorbate did not gain any noteworthy its advantageous use for preserving certain which are especially sensitive to pH has been A process for the manufacture of an of sorbic acid has been found containing from 12 to ho parts by weight of sorbic acid at a warm solution is optionally purified by means of an adsorbent and crystallized by cooling to room The tion of the composition according to the invention can be pared by dissolving sorbic acid at a temperature of from to in potassium sorbate But it is possible as well to blend a sorbic acid solution with such a quantity of potassium hydroxide that the sorbic acid is partially tralized and a solution is produced with a content of sorbic acid and potassium sorbate as An purification is advantageous in case that at the base of the process is an unpure or crude sorbic acid or an unpure or crude potassium As adsorbents taken into consideration the usual porous and e substances such as active bentonite as well as adsorption Preference is given to the use of a coal the preparation of which is based on pit coal containing less than weight of The sorbic acid potassium sorbate solution may be processed with an with the active coal pared from pit continuously or When operating the active coal is advantageously suspended its finely puverulent form in the hot sorbic potassium sorbate solution and kept in motion by agitation or On the other the use of a granular active coal is recommended for a continuous processing The coal may be setup in that case in a column or in a system prising several consecutive columns or suitably constructed towers which may be installed either stationary or as a The sorbic acid potassium sorbate solution is conveyed through the respective installation either from the bottom to the top or in case of a in a parallel flow or return As far as the adsorptive purification of the sorbic acid potassium sorbate solution on an industrial scale is the continuous processing method is For this purpose it is most useful to clude oxygen as far as possible by means of an inert gas phere such as While the which is optionally purified is cooling the adduct of sorbic acid potassium sorbate The size of the crystals depends tially on the speed of cooling and lization product is then separated in the usual by centrifagation or sue Since potassium sorbate is subject to decomposition into its components while being washed with the potassium sorbate being dissolved and the scarcely sorbic acid being eventual washing process is reconimendably carried out with an organic solvent such as it is generally more useful especially when operating nuously to dry the product directly without an intermediate washing so that a potassium disorbate is obtained which contains approximately to 2 weight of potassium sorbate more depending on the size of the crystals than the molar composition of the adduct would normally The yield based on the sorbic acid charged in the depends sentially on the quantitative proportion of the initial The yield is from to if an aqueous lution is prepared which contains from 12 to 20 weight of sorbic acid and weight of potassium After having removed the crystallized potassium the mother solution containing an excess of potassium bate may be practically so that the process according to the invention is very Further the special advantages of the process as per the tion consist in the facts that it is possible to start from a crude sorbic acid and that the potassium disorbate produced in this way is extremely The following examples illustrate the inventions A L E 120 g of sorbic acid are dissolved in a solution of of potassium sorbate in ml while heating to and After having cooled to room the crystals are sue washed with 100 ml of acetone and dried in a vacuum shelf dryer nun at 266 g of potassium disorbate calculated on sorbic E X A M P L E 200 g of sorbic acid are dissolved at in a solution of 00 g of potassium sorbate in 400 ml of After cool ing to room washing with acetone and drying in vacuo at there are obtained g of potassium disorbate calculated on sorbic A P L 3 25 1 of active coal on pit granulations 2 which had been freed from iron by sulfuric acid and subsequently neutralized by washing with were char ged into a tube having a length of 10 m and being equipped with a heating jacket in such a that no gas bubbles are formed while At a ture of 75 a solution prepared at of 56 part by weight of sorbic acid parts by weight of potassium hydroxide at and of 2 parts by weight of water is pumped through this column a gen atmosphere from the bottom to the top at an hourly rate of The purified solution is filtered while still hot and cooled to room temperature within the next The crystallization product is removed by centrifugation and dried in vacuo at kg of potassium disorbate are obtained which contains from weight of potassium sorbate more than the stoichiometric quantity wou d stand The yield is from 8 calculated on the sorbic acid The mother liquor is solution of parts by weight of crude sorbic acid and of parts by weight of potassium hydroxide in 100 parts by weight of mother insufficientOCRQuality

Claims

1. 47436/2 What 1s claimed Is:

2. 1. A process for the manufacture of an addition-compound of sorbic ac d and potassium sorbate having the formula CgHgOg. ¾Η7¾Κ wh ch comprises the preparation of a solution containing from 12 to 40 parts by weight of sorbic acid per 100 parts by weight of an aqueous (40 - 58 weight 2) potassium sorbate solution at a temperature of from 45 - 5°C the warm solution 1s optionally purified by means of an adsorbent and crystallized by cooling to room temperature. 2i A process according to claim 1 , wherein 12 to 40 parts by weight of sorbic a id are dissolved In 100 parts of an aqueous (40 - 58 weight %) solution of potassium sorbate by heating 1t to a temperature of from 45 to 95°C.

3. A process according to claim 1 , wherein the aqueous solution of sorbic acid - potassium sorbate is prepared by a partial neutralization of a solution of sorbic add with potassium hydroxide.

4. A process according to claim 1 , whereln the adsorptlve pur fication an activated carbon prepared from pit coal Is feed.